JP2001270950A - Film for decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film for a decorative sheet made of a polyolefin resin excellent in roll-releasing properties in molding as well as excellent in appearance. SOLUTION: The film for a decorative sheet is made of a polyolefin resin satisfying equations (1) and (2) [wherein Tc (the crystallization temperature of the resin)=80-125 deg.C; MFR(melt flow rate)=1-10 g/10 min (230 deg.C); and Hc (the crystallization energy of the resin)=50-250 J/g]. Log(Tc)×log(MFR)=0-2...(1) log(Tc)×log(MFR)×log(Hc)=0-3.5...(2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film used as a resin decorative sheet for decorative materials such as interior materials of furniture and buildings, surface decoration of fittings, plastic decorative plywood for home appliances and plastic coated steel sheets. It is about.

[0002]

2. Description of the Related Art A polyolefin resin film used for a decorative sheet or the like is formed by extrusion molding or the like, and the film is embossed as required. When embossing the film in the extrusion molding of the polyolefin resin film, the molten resin usually coming out of the T-die is nipped (sandwiched) between two rolls of a rubber roll and a metal emboss roll without cooling. ) The emboss is transferred to the film, but after the nip, the peeling of the molten resin from the roll, especially the rubber roll, becomes uneven, and the appearance of the film is poor, such as traces of roll separation, the film thickness is poor, and the resin peels from the rubber roll. Without this, many defects such as winding on a rubber roll and defective molding occurred. This phenomenon was remarkably observed particularly when forming a thick product having a thickness of 0.1 mm or more.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a film for a decorative sheet made of a polyolefin resin which is excellent in roll releasability during molding and excellent in appearance.

[0004]

The gist of the present invention resides in a decorative sheet film made of a polyolefin resin satisfying the following formulas (1) and (2).

[0005]

LOG (Tc) * LOG (MFR) = 0 to 2 (1) LOG (Tc) * LOG (MFR) * LOG (Hc) = 0 to 3.5 (2) ( Where Tc (crystallization temperature of resin) = 80 to 12
5 (° C.), MFR (melt flow rate) = 1 to 10
(G / 10 minutes, 230 ° C), Hc (crystallization energy of resin) =
50 to 250 (J / g))

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have studied the relationship between the resin composition and the roll releasability, and found that the crystallization temperature (Tc),
Relationship between melt flow rate (MFR) and roll release property,
Further, regarding the relationship between the three factors obtained by adding the parameter of crystallization energy (Hc) to the above two parameters and the roll releasability, the roll releasability is good in a specific numerical range in a certain calculation formula, and It has been found that no molding defects occur, and the present invention has been accomplished.

Hereinafter, the present invention will be described in detail. The polyolefin resin used for the decorative sheet film of the present invention satisfies the following formulas (1) and (2). In addition, the bottom of LOG is 10 in the formula.

[0008]

LOG (Tc) * LOG (MFR) = 0 to 2, preferably 0.1 to 1.5 (1) LOG (Tc) * LOG (MFR) * LOG (Hc) = 0 3.5, preferably 1-3 (2) (where Tc (crystallization temperature of resin) = 80-12)
5 (° C.), MFR (melt flow rate) = 1 to 10
(G / 10 minutes, 230 ° C), Hc (crystallization energy of resin) =
(50 to 250 (J / g)) When the value of the expression (1) is less than 0, this is the MFR of the resin.
May be less than 1, but in such a case, the ejection of the resin from the extruder is not stable, and a thickness defect such as a surging phenomenon occurs. When the value of the expression (1) exceeds 2, this is because, for example, Tc is 130 ° C. and MFR is 9 (g / 10 min).
, And when Tc is 120,
As in the case where the MFR is 16 (g / 10 min.)
Although the FR may be large, in the former case, the resin discharged from the extruder is cooled to near the temperature before being nipped between the rubber roll and the metal roll, so that the emboss transfer property due to the nip is inferior, and the transfer property is poor. By increasing the nip pressure between the rubber roll and metal roll,
The linear pressure at the contact point between the rubber roll and the molten resin increases, and the molten resin is pressed into the rubber roll with an excessive pressure, which may result in poor resin roll releasability. In the case of the latter, the melt tension of the resin discharged from the extruder is small, and after the nip, the resin cannot withstand the tension required to separate the resin from the rubber roll, making it difficult to separate from the rubber roll.

Further, it is preferable that the value of the formula (1) is from 0.1 to 1.5, since the releasability of the film from the rubber roll is particularly excellent. When the value of the expression (2) is less than 0, the MFR of the resin may be less than 1, but the problem in this case is as described above. When the value of the formula (2) exceeds 3.5, the Tc is 130 ° C. and the MFR is 6 (g / 10 minutes).
In some cases, as in the case where Hc is 150 (J / g), Tc is large. In this case, as described in detail in the description of the expression (1), the emboss transferability is poor, or the roll separation of the film occurs. May be inferior.

When the value of the expression (2) is from 1 to 3, the film is particularly excellent in the releasability from the rubber roll, and the film is excellent in rigidity.
Tertiary processing is easy and particularly preferable. In the present invention, the crystallization energy (Hc) is defined as the difference between the melting point and the melting point of the resin once measured by differential scanning calorimetry.
DSC chart (melting curve) when cooled at a rate of / min
The crystallization temperature (Tc) is the value of the peak temperature in the DSC chart.

The polyolefin resin used in the present invention includes a polypropylene resin, a polyethylene resin and a mixture thereof. Examples of the polypropylene resin include a homopolymer and / or copolymer of propylene, and a mixture (polymer blend) of the homopolymer and / or copolymer with another polymer. Examples of the copolymer include a random copolymer or a block copolymer of propylene and ethylene or another α-olefin, or a propylene graft copolymer having a polyolefin copolymer as a trunk polymer. . Among them, a random copolymer is preferable because the transparency and flexibility of the film are improved. As the α-olefin copolymerizable with propylene, ethylene and those having 4 to 12 carbon atoms are preferable.
Examples thereof include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, and 1-decene, and one or a mixture of two or more thereof is used. The mixing ratio of the α-olefin is preferably 1 to 10% by weight, particularly preferably 2 to 6% by weight based on propylene.

Examples of the polyolefin copolymer for the backbone polymer of the propylene graft copolymer include ethylene-propylene rubber, ethylene-butene rubber, and ethylene-propylene-diene rubber. Examples of the polymer which can be mixed with the homopolymer and / or the copolymer to give a polymer blend include:
For example, diene rubbers such as isoprene rubber, butadiene rubber, butyl rubber, propylene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-isoprene rubber, ethylene-propylene copolymer rubber, ethylene-propylene non-conjugated diene rubber, ethylene-butadiene Examples include a polyolefin thermoplastic elastomer such as a copolymer rubber and a styrene thermoplastic elastomer such as a styrene-butadiene rubber and a styrene-isoprene rubber. Among them, a styrene-butadiene-based thermoplastic elastomer is preferable. The styrene-based thermoplastic elastomer is preferably hydrogenated. The amount of the polymer to be mixed is preferably from 10 to 80% by weight, particularly preferably 20 to 80% by weight.
~ 60% by weight is preferred.

Examples of the polyethylene resin include a homopolymer of ethylene and a copolymer containing ethylene as a main component (low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), metallocene Or a mixture (polymer blend) of the homopolymer and / or copolymer with another polymer. As the other polymer,
What was mentioned in the description of the polypropylene-based resin can be used.

Furthermore, it is preferable that the film for a decorative sheet of the present invention contains an ultraviolet absorber and / or a hindered amine light stabilizer. Examples of the ultraviolet absorber include benzotriazole-based, benzophenone-based, and benzotriazine-based ultraviolet absorbers. In particular, a benzotriazole-based ultraviolet absorber and a benzotriazine-based ultraviolet absorber are preferable because the film is less colored.
Among the benzotriazole-based UV absorbers,
Molecular weight 380-1000, preferably 400-800
Is preferred because it hardly blooms and has good compatibility with the polypropylene resin.

[0015] As such a benzotriazole ultraviolet absorber, 2- [2'-hydroxy-3'-
(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole (molecular weight 388), 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) ) Phenyl] -2H-benzotriazole (molecular weight 448), 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl-6)
-(2H-benzotriazol-2-yl) phenol] (molecular weight 659).

As the benzophenone-based ultraviolet absorber,
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Octoxybenzophenone, 2,2'-dihydroxy-
4-dimethoxybenzophenone, bis (2-methoxy-
4-hydroxy-5-benzoylphenyl) methane and the like.

As the benzotriazine type ultraviolet absorber, 2,4-bis (2,4-dimethylphenyl) -6-
(2-hydroxy-4-n-octyloxyphenyl)
1,3,5-triazine, 2- (4,6-diphenyl-
1,3,5-triazin-2-yl) -5-((hexyl) oxy) -phenol and the like. The blending amount of the ultraviolet absorber is preferably 0.01 to 10 parts by weight, particularly preferably 0.05 to 10 parts by weight, per 100 parts by weight of the polyolefin resin.
5 weight is preferred. If the amount is less than 0.01 parts by weight,
The effect of preventing browning / deterioration tends to be insufficient, and even if used in an amount exceeding 10 parts by weight, the effect corresponding to the content cannot be obtained, and bleeding may occur.

As the hindered amine light stabilizer, bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate, bis (1,2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate
2,2,6,6-pentamethyl-4-piperidyl), dimethyl-1- (2-hydroxyethyl) -4-succinate
Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate and poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4
-Diyl {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene} (2,2,6,6
-Tetramethyl-4-piperidyl) imino}]. Among them, dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (molecular weight 3100 to 400)
0) or poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} (2,2,6,6-tetramethyl- 4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}] (molecular weight 200
0 to 3100), or a copolymer of a polyethylene resin and a hindered amine light stabilizer having an unsaturated group, the bloom of the hindered amine light stabilizer itself can be reduced. It is more preferable. As the polyethylene resin obtained by copolymerizing the hindered amine light stabilizer, those having a melt flow rate in the range of 1 to 10 (g / 10 minutes) are considered from the viewpoint of compatibility with the polyolefin resin as the base resin. preferable.

The amount of the hindered amine light stabilizer is as follows:
0.01 to 1 per 100 parts by weight of polyolefin resin
It is preferably 0 parts by weight. If the compounding amount is less than 0.01 parts by weight, the stabilizing effect may be insufficient.
When used in excess of parts by weight, the effect corresponding to the content may not be obtained, and bloom may occur. In the decorative sheet film of the present invention, if necessary, an antioxidant agent,
A slip agent, a coloring agent, a filler, a nucleating agent and the like may be added within a range that does not impair the purpose of the present invention. As for these additives, it is common to use a high-concentration compound (master batch) in a polyolefin resin in advance.

The method for producing the film for a decorative sheet of the present invention may be a general method for forming a film made of a polyolefin resin, such as a T-die extrusion molding method, an inflation molding method, and a calendar molding method. Not done. The thickness of the film for a decorative sheet of the present invention,
Depending on the application site (used as a single layer or used as a surface layer, print layer, base layer, etc.) and the layer structure of the decorative sheet as the final product, the strength and post-processing of the entire decorative sheet, Alternatively, from 0.1 to 0.5 in terms of ease of handling.
mm is preferable.

A decorative material can be manufactured by laminating such a decorative sheet on a base material such as plywood or steel plate using an adhesive or an adhesive.

[0022]

The embodiments of the present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. <Evaluation test method> (1) Crystallization energy In the differential scanning calorimetry, the resin was once melted at a temperature equal to or higher than the melting point, and then cooled at a rate of 10 ° C./min from the crystal peak area of the DSC chart (melting curve). Calculation. (2) Crystallization temperature The value of the crystallization peak temperature in the DSC chart. (3) Melt flow rate Measured according to ASTM D1238. (4) Roll Peelability The peelability of the film and the rubber roll after the nip between the metal roll and the rubber roll was visually evaluated.

A: The appearance of the film is good. X: Roll appearance marks and poor appearance. <Examples 1 to 5 and Comparative Examples 1 to 3> Dies were extruded using a resin composition having the composition shown in Table 1 with a T-die extruder (T-die manufactured by Plagiken Co., Ltd .: 400 mm width). Immediately after extruding the resin from the dice at a temperature of 230 ° C., a metal roll and a rubber roll are used to nip the resin to a thickness of 0.1
A 2 mm film was made. The obtained film was evaluated. The results are shown in Table 1.

[0024]

[Table 1]

[0025]

Industrial Applicability The film of the present invention has good roll separation, excellent productivity and good appearance, and is suitably used as a film for a decorative sheet.

Claims (2)

[Claims] 1. A decorative sheet film comprising a polyolefin resin satisfying the following formulas (1) and (2). LOG (Tc) * LOG (MFR) = 0-2 (1) LOG (Tc) * LOG (MFR) * LOG (Hc) = 0-3.5 (2) (1) Where Tc (crystallization temperature of resin) = 80 to 12
5 (° C.), MFR (melt flow rate) = 1 to 10
(G / 10 minutes, 230 ° C), Hc (crystallization energy of resin) =
50 to 250 (J / g)) 2. The method according to claim 1, wherein the thickness is 0.1 to 0.5 mm.
A film for a decorative sheet according to item 1.